Which version of Caffeine are you running? The version in master has support for customisation:

I can't remember if this has made it to a release or not yet, but a new one should be coming out soonish, whenever the GNOME 45 port is merged.

Ah, looking at the merge history, v45 was the first version to allow configuration, currently only Debian testing and unstable have v48.
The latest version of master currently supports GNOME 43 and 44, since you're on Debian stable, this should be supported.

I don't know if it'll get backported, it seems unlikely as it's not a very important package, so you may be better off installing from source, or installing from https://extensions.gnome.org/extension/517/caffeine/ instead.

This is the current range timers:

• 5, 10, 30 minutes
• 10, 20, 45 minutes
• 15, 30, 60 minutes
• 20, 40, 75 minutes
• 30, 50, 80 minutes

Let me knows if it need adjustment.

@pakaoraki I'm so sorry to bother you, but I was just wondering, why don't you support custom inputs, for example three input boxes next to each other.

I would like to have even a higher range timer. Some use cases:

• When using two computers and I want to see the status of a task that takes long to execute in the other
• When I want to execute a very long task over night while I sleep

An extra range timer with 30 minutes, 2 hours, 8 hours would fit this needs.

I also like the idea of custom inputs. In that case, I think it would be nice to show any multiple of 30 higher or equal than 60 in hours in the menu (example: 20 minutes , 30 minutes, 1 hour, 80 minutes, 1.5 hours, 4 hours, 260 minutes, 5.5 hours, 365 minutes).

In general, it would also be nice to display times as HH:MM:SS (instead of the current MM:SS) for times longer than an hour. Examples: 2:32, 12:32, 1:12:32, 11:12:32.

I will propose a revamp with custom values:

I will propose a revamp with custom values:

Ooh looks good, I'd be happy to review that if you submit a PR

I'll try to PR this soon.